I can provide examples of the shapes that people have drawn:
Transmasc Pikachu with stitched tail: https://www.furaffinity.net/view/39071465/
Intersex Pikachu (not fully heart or square): https://www.deviantart.com/twinkel13/art/Intersex-Pikachu-561094460
Flame Tail Nonbinary Pikachu: https://www.deviantart.com/lovelatias/art/Non-binary-pikachu-706846661
Double Triangle Tail Nonbinary Pikachu: https://www.deviantart.com/attemptinggood/art/Gender-neutral-Pikachu-903517742
Also, things can get even more interesting to think about when we throw intersex into the equation.
Where this gets even more interesting is: Some transmasc Pikachu art features the two sections of the "heart" tail stitched together. As for how the transfem Pikachu counterpart to that would work, my guess is that it would involve reshaping of the tail.
As for Pikachu tails on Pikachus that are not male or female look, there are several ways people draw those: Some are drawn in a way that differs majorly from heart or square tails, one example being a mostly-triangular end, somewhat modeled after flames. One intersex Pikachu artwork I saw is one where half the tail is heart, the other half square. A theoretical ADDITIONAL way to draw a non-masc non-fem Pikachu tail is for the tips of a heart Pikachu tail's hearts to be a shape that is not round, so something like a triangle, square (so a notched square tail), or something else, or to have the entire tail end be an arbitrary shape. Or you could have the whole tail end in a circle. There are MANY ways to draw a Pikachu tail that is not masc or fem.
I would say that a fursona species that would have heavy vibes with trans people would be species capable of shapeshifting. My fursona is effectively an anthropomorphic version of the feline shape-shifting Pokemon known as Mew, but specifically the shiny form.
My response: yes
I get rid of my body hair.
Thanks!
I had to deal with a binary-only form at my dermatologist, and I went Costco shopping and I'm drained, especially after the dentist. I have an endocrinology lab tomorrow. Otherwise, I'm fine.
I'm actually intersex (I have multiple intersex conditions), but in a manner closer to AMAB than AFAB. Now, admittedly, my first sona's original incarnation at its original inception was essentially that (what you mentioned) to some degree. My transition options in the end ultimately are ones involving a PPV with no orchi.
The first LGBTQ+ person I ever ran into online was a transmasc furry artist. I had already been in the furry fandom for a short while before seeing his content. It wouldn't be for another relatively-short while that I would realize my actual gender. However, had his art not been seen by me, it is possible my story would have been completely different. His art was my first introduction to characters with body types outside the gender binary. Oh, and his art style is amazing. I wish I could remember his handle.
Now, I've found on Discord that MANY LGBTQ+ people I have ran into over the last 6 years of my Discord use have been furries.
As for what gender my original 2018 sona was: In a sense, it reflected that I was completely not hyperbinary but also a trans girl, at least in comparison to who I am now as a nonbinary person not beholden to the gender binary. This sona even used neopronouns, something I myself did not really use for myself at the time. It's a topic that is quite a feffadoo (a neologism I coined from the magic number of my program BWTC32Key) given that even looking at my notes app from back then on my oldest Android device (it was used as an interim device during SD card upgrading of my main phone and my main backup) provided me with more questions than answers. Looking at some writing files around a year prior on my Dropbox also prompted more questions than answers on the same topic. I can't say for certain as to what my degree of binary trans status was back then, but I can say what it wasn't. I wasn't at all hyper-binary. I would say that the furry community was where I ran into a large amount of the binary being escaped from.
In fact: the ey/em in my neopronouns exists because of ey/em being used by one particular fursona out there that totally related to me and is also an ambonec (both and neither binary gender, which is essentially what I am, even now.)
Oh and the entirety of my fursonas are nonbinary.
Now when it comes to gaming on Valve games... That community often wasn't the nicest to non-cishetmono people. I have plenty of stories on that topic, which I will spare you from. Meanwhile, the furry sites and community, even back in those times (2018), had a large amount of LGBTQ+ content and creators, which is a good thing.
As for other things: I did use my sona as a test bed for neopronouns (as detailed earlier). Oh, and the concept of a shy and sensitive inner male sona did apply in very late 2017 or so. In a sense, this sona harked back to one of the more intriguing characters by the furry artist I mentioned earlier who I can't remember the name of.
Also, I grew up in a sheltered upbringing, and the furry fandom let me be myself. To this day, I use technology and the internet as an escape from my real life.
I will ALSO say that I'm an otherkin. Oh, and as for my fursona species: it's a Pokemorph of Mew's Shiny form (Mew is a shy genderless shapeshifter Pokemon).
TL; DR: The furry community was VERY formative to my journey.
Thanks!
I have a template at http://stgiga.github.io/gigaware/5box.png which has more boxes for more reactions.
Birds use chromosomes Z and W. ZZ is masc, ZW is fem.